350MW超临界供热机组汽轮机通流改造研究

Research on Steam Turbine Flow Path Modification of 350MW Supercritical Heat Supply Unit

针对某350MW超临界供热机组供热能力不足、通流效率低、汽封漏汽量大、安全可靠性不高、中低负荷经济性差等问题,从调节级、通流级、汽缸结构、排汽优化、汽封技术、末级叶片选型、供热方式、中低负荷提效等方面对改造方案的新技术和原有技术进行了对比分析和论述,给出目前最合理的改造方案,并对改造后的经济性效果进行评价。结果表明,通流改造后的机组经济性和安全性在纯凝工况和供热工况下较改造之前都有显著提高。

Aiming at the problems of a 350 MW supercritical heat supply unit,such as insufficient heat supply capacity,low flow efficiency,large steam seal leakage,low safety and reliability,and poor economy of medium and low loads,the new technology and the original technology of the transformation scheme are analyzed and discussed from the aspects of regulating stage,flow stage,cylinder structure,steam exhaust optimization,steam seal technology,last stage blade selection,heat supply mode,and efficiency improvement of medium and low loads,The most reasonable transformation scheme is given at present,and the economic effect after transformation is evaluated.The results show that the economy and safety of the unit after the flow passage transformation are significantly improved under the conditions of pure condensation and heat supply compared with those before the transformation.